Primary skin infections with opportunistic fungi

Primary cutaneous infections with opportunistic fungi of the genera Aspergillus, Mucor/Rhizopus, and Cryptococcus are rare forms of locally invasive disease. The majority of these cases involve immuno-compromised patients with a definable inoculation site unrelated to a pre-existing systemic infection. Cutaneous cryptococcosis may present as ulcers, cellulitis, pustules, or mimic viral manifestations. Aspergillus and Mucor/Rhizopus lesions begin as small erythematous nodules which over several days ulcerate and form a black necrotic eschar. Diagnosis of cutaneous mycotic infections is reliant upon a high clinical suspicion and rapid (and necessary) diagnosis may be made by direct microscopic examination of curettings of the lesion. Treatment is with amphotericin B, and surgical debridement when indicated. Diagnostic urgency is mandatory for Aspergillus and Mucor/Rhizopus skin involvement because of destructive nature of infectious process with tendency toward systemic spread.